The present invention relates to a novel thermoplastic resin composition which contains a polyphenylene ether resin and a polyamide resin.
Polyphenylene ether resin is a thermoplastic resin superior in various properties such as mechanical properties, heat resistance and dimensional stability. However, polyphenylene ether resin itself is considerably inferior in impact resistance and solvent resistance, and is unsatisfactory in processability due to its high melt viscosity. Polyamide resin is a thermoplastic resin superior in mechanical properties, solvent resistance and processability, but is inferior in impact resistance and heat resistance and besides, inferior in dimensional stability due to its high water absorption. In order to offset one disadvantage by one advantage, blends of the two resins have been proposed. However, blends of only the two resins lose the superior mechanical properties they possess. Therefore, it has been proposed to improve the dispersibility and the mechanical properties by adding various compatibilizing agents at the time of blending of polyphenylene ether resins and polyamide resins. The proposals are disclosed in Japanese Patent Kokoku Nos. 60-11966 and 61-10494 and Japanese Patent Kokai Nos. 59-66452 and 56-49753. The resulting PPE/nylon resin compositions are being increasingly applied to electric and electronic fields and automotive field. Furthermore, in order to improve dimensional stability when absorbing water and solvent resistance of these PPE/nylon compositions, Japanese Patent Kokai Nos. 2-305854, 2-284955 and 2-656 propose the resin compositions to which polyolefins are added, but these compositions are still insufficient in balancing of rigidity, impact strength and adhesion of coating film.